United States coins (aside from those of the earlier colonial coins) were first minted in 1792. Since then they have been produced annually in denominations of 1¢ (i.e. 1 cent or $0.01), 5¢, 10¢, 25¢, 50¢, and $1.00. The most interesting coins for collectors often include those that circulated for just a short time. Numismatics and Coin collecting are different in that the former is the systematic study of currency as a whole, though the two disciplines are closely interlinked. Professionally graded coins that are authenticated and encapsulated by organizations such as PCGS and NGC, are very desirable for the average collector as well as serious investors.